System and method for high resolution wireless full disclosure ECG episode monitoring and analysis

ABSTRACT

High resolution full disclosure ECG data is transferred from a body sensor device to a handheld device via a wireless protocol. The handheld device transfers the full disclosure ECG data via a cellular network to a data center for analysis. A monitoring center communicating with the data center facilitates technician and physician review and interactions.

BACKGROUND

The present invention generally relates to a wireless full disclosureanalysis and monitoring system and, in particular, an ECG analysis andmonitoring system used for the diagnosis of cardiac arrhythmia inambulatory patients.

Remotely monitoring ambulatory patients for arrhythmia and promptlynotifying a caregiver when a serious arrhythmia has been discoveredpresents many challenges. ECG (electrocardiographic) signals detected bya remote monitor are subject to noise from both patient movement andenvironmental sources. This noise must be reduced sufficiently to allowaccurate reproduction of the ECG signals and accurate analysis of anyarrhythmias present in that signal. In addition, the arrhythmia analysisalgorithm must operate in a resource constrained, embedded system.

In some approaches, wide area wireless communications are employed inorder to allow the transmission or notification of serious arrhythmiasto the caregiver while the patient is ambulatory. However, wirelesstransmission is expensive in terms of both power consumption and airtimecharges. In addition, wide area wireless network coverage is not alwaysavailable in all areas, especially in patient's homes. In order tomaintain the ability to notify a caregiver of a serious arrhythmia withlow latency (near-real time), an alternate communication path is oftenrequired in the patient's home.

In order to manage power consumption and airtime charges, as well as thetechnician time it takes to review the transmissions, some approacheshave limited remote monitor transmissions to as low a rate as possibleby reducing the arrhythmia algorithm sensitivity to the minimum levelsneeded to maintain adequate diagnostic capability. Achieving the correctbalance of algorithm sensitivity to positive predictivity in order tolimit the amount of data transmitted can be challenging in the presenceof signal artifact and when the patient exhibits a chronic arrhythmia.

Thus, there is a need for a cost effective remote monitoring system thatcan provide reliable full disclosure ECG analysis and reliablearrhythmia detection and transmission of samples of serious arrhythmiasquickly to a caregiver, 24 hours a day. In particular, there is a needfor a cost effective remote monitoring system that can provide reliablefull disclosure analysis and reliable detection and transmission ofsamples of serious arrhythmias quickly to a caregiver, 24 hours a day.

SUMMARY

In one form, the invention provides high resolution, full disclosuredata acquired at the patient on a body worn sensor.

In another form, the invention provides high resolution, full disclosureECG (electrocardiographic) data acquired at the patient on a body wornsensor. The full disclosure ECG data is stored and then transmitted to ahandheld device using a local area wireless technology such asBluetooth™. The handheld device stores and transmits the data via acellular network to a data center. At the data center, all fulldisclosure ECG data is stored and then analyzed for arrhythmia. The fulldisclosure ECG data including the portions containing arrhythmicepisodes are transmitted to a monitoring center for analysis andconfirmation by a technician before being compiled into a report andtransmitted to a physician. The system also allows for real time 2-waycommunications of voice and text messages between the patient and thetechnician or physician.

Other features will be in part apparent and in part pointed outhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment of a system of theinvention.

FIG. 2 is a block diagram of another embodiment of the system of theinvention including a POTS modem.

FIG. 3 is a block diagram of one embodiment of the EAPS (ECG Analysisand Processing Subsystem) architecture of the data center of FIG. 2.

FIG. 4 is a block diagram of one embodiment of the algorithm instance ofthe data center.

FIG. 5 illustrates a ventricular fibrillation and/or SADA algorithm.

FIG. 6 is a graphical representation of rate- and rhythm based sampleidentification limits of the algorithm instance of the data center ofFIG. 4.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DESCRIPTION

The present invention as shown in FIG. 1 is a system 100 for use by apatient P having access to a cellular network CN. A body sensor device102 is adapted to be worn by the patient P has a sensor circuit 104, asensor processor 106, a sensor storage memory 108 and a sensortransmitter 110. The sensor circuit 104 detects full disclosure data ofthe patient P, such as ECG data. In one embodiment, the sensor circuit104 comprises leads 112 attached to the patient's skin and providing asampled analog full disclosure ECG signal. The sensor processor 106converts the sampled signal to full disclosure ECG data and stores thefull disclosure ECG data in the sensor storage memory 108, and thesensor transmitter 110 transmits a full disclosure ECG(electrocardiographic) signal 114 including the full disclosure ECG datastored in the sensor storage memory 108. In one embodiment, the sensordevice 102 is energized by one or more AAA batteries which are changedevery day. The sampled full disclosure ECG signal acquired by the bodysensor device 102 from the sensors 112 comprises at least 2 channels,each providing a high resolution [e.g., in the range of about 10 to 1.25uV per bit] full disclosure ECG acquisition signal (up to 1.25microvolts per bit, 1000 Hz 16 bit samples per second, dynamic range of+/−40 mV, 0.05 to 150 Hz bandpass). In one embodiment, the processor 106of the body sensor device 102 incorporates a muscle artifact rejectionalgorithm for noise rejection. In another embodiment, the data center142 includes a muscle artifact rejection algorithm for noise rejection.

In one embodiment of the sensor device 102 in which the sampling rate is1000 Hz, a low-pass FIR filter is used to downsample the data. Theresult of this filter is divided by 32768 (e.g., bit-shift by 15). Todownsample the original data, this filter is run once every 4 samples,therefore, the output frequency will be 1000/4=250 Hz.

In one embodiment, the sensor device 102 may be provided with a displaysuch as a multicolored LED 116 driven by the processor 106. Theprocessor 106 would be programmed to flash the LED 116 red to alert thepatient of a serious event or a device malfunction, orange to indicatean alert condition and green to indicate a no-alert condition and thedevice is functioning properly. Alternatively or in addition, a vibrator118 may be included with the device 120 to also alert the patientwearing the device of the event. Alternatively or in addition, a speaker120 or other sound producing device may part of the sensor device toprovide an audible alert to the patient.

A handheld device 122 is adapted to be carried by the patient P andincludes a handheld storage memory 124, a handheld processor 126, ahandheld receiver 128 and a handheld transmitter 130. The handheldreceiver 128 receives the full disclosure ECG signal 114 from the bodyworn sensor device 102 and the handheld processor 126 stores the fulldisclosure ECG data included in the received full disclosure ECG signalin the handheld storage memory 124. Optionally, the body sensor device102 and the handheld device 122 communicate via a low power Bluetooth(BT class 3) technology for power saving. The handheld transmitter 130transmits a packet signal 132 including the full disclosure ECG datastored in the handheld storage memory 124 via the cellular network CN.

In one embodiment, the handheld device 122 is energized by arechargeable battery and comprises an integrated application andbaseband processor in a pre-certified cellular communications modulesuch as a Q2687 module by Wavecomm thereby providing lower cost andlower complexity.

In one embodiment, the handheld device 122 may be provided with adisplay such as an alphanumeric display 134 driven by the processor 126.The processor 126 would be programmed to display text messages to thepatient P on the display 134. In addition, other menu items on thedisplay 134 may include device information, wireless settings, batterylevels, volume controls, and record symptoms (by which the patient canrecord their symptoms at any instant in time). In one embodiment, it iscontemplated that the display 134 may indicate the battery levels ofboth the sensor device 102 and the handheld device 122. In thisembodiment, the sensor device 102 would transmit information indicatingits battery level to the handheld device 122 for display.

Alternatively or in addition, a sound transducer 136 or other sound orlight producing device may part of the handheld device 122 to transmitaudible messages to and from the patient P. In one embodiment, thedisplay 134 of the handheld device 122 may be driven by the processor126 to display one or more smart keys, soft keys and/or a soft keypadwhich have various functions depending on the screen that is beingdisplayed. An icon or word may appear on the screen adjacent to eachsmart key to identify its function. Also, the handheld device 122 may beprogrammed such that the processor 126 generates a low frequency singleor dual tone regular/low frequency alert indicator via the soundtransducer 136.

In one embodiment, it is contemplated that the sensor storage memory 108and/or the handheld storage memory 124 each be configured to store atleast 30 days of full disclosure ECG data storage. This would serve as aback up to the full disclosure ECG data in the situation wheretransmission of the data does not occur for some reason. For example,the sensor storage memory 108 and the handheld storage memory 124 wouldeach be about two (2) gigabytes. Preferably, the handheld devicesupports at least 2 GB of non-volatile storage for full disclosure ECGdata and other files. All full disclosure ECG data will maintain theserial number of the sensor 102 from which it was acquired as well as atimestamp supplied by the sensor 102. Thus, redundant data copies areavailable from the data center and from the handheld device and/or thesensor device.

Each device 102, 122 may also include a flash card memory as its storagememory for storing the data and an external USB interface for remoteaccess by a second device for such purposes as data transfer to/from thesecond device, and for device configuration, provisioning, anddiagnostics.

A data center 142 remote from the patient P has a data center receiver144, a data center processor 146 and a data center storage memory 148.The data center receiver 144 receives the packet signal 132 from thehandheld device 122 and the data center processor 146 stores the fulldisclosure ECG data included in the received packet signal 132 in thedata center storage memory 148. The data center processor 146 includesanalysis software executed by the processor 146 to analyze the fulldisclosure ECG data stored in the data center storage memory 148. Thesoftware conducts waveform analysis to identify any anomalies (e.g.,abnormal ECG waveforms) in the full disclosure ECG data stored in thedata center storage memory 148. This configuration permits the datacenter 142 to process the full disclosure ECG data from multiplepatients simultaneously.

In one embodiment, the data center processor 146 includes software whichprovides a navigable waveform or “map” that provides drill down accessto portions of a particular day's full disclosure ECG data. Thus, atechnician via the technician device 168 or a physician via thephysician device 172 can view reports or summaries of the fulldisclosure ECG data and drill down to fundamental full disclosure ECGdata on which to reports or summaries are based. In addition, thesoftware may present a secondary measure such as heart rate or noiselevel of the full disclosure ECG data. For example, the data centerprocessor 146 permits the technician and/or the physician to view thestored full disclosure ECG data in low resolution [e.g., 24 hours acrossa page] and to drill down selected full disclosure ECG data to a higherresolution [e.g., 8 seconds across a page]. The data center may permitthe technician and/or the physician to view the stored full disclosureECG data of a particular period of time and to view related ECG data tothe particular period of time. For example, related data may include ECGdata before or after the particular period of time and may include otherparameter data during, before or after the particular period of time.

In one embodiment, the data center is configured as expandable(scalable) so that additional processors 146 may be added to handleadditional sensor/handheld combinations.

A monitoring center processor 162 linked to the data center 142 by awired or wireless network 164 provides review of the data samples ofarrhythmia in high resolution full disclosure ECG data. The data samples(herein “markers” or “pointers”) are portions of the high resolutionfull disclosure ECG data and not merely an indication of detectedevents. Since the processor 162 has full disclosure data available, aprimary purpose of this embodiment is to identify and provide to thetechnician the portions of data of arrhythmias contained in the fulldisclosure data. Simultaneously, the technician continues to have accessto all full disclosure ECG data, not just an indication of events oronly the identified samples, so that the technician can scroll backwardor forward from a point of view within the data to evaluate the dataprevious in time to the point of view or subsequent in time to the pointof view. Providing markers or pointers is different from detectingevents based on predefined limits and transmitting only those events(containing ECG data) to the technician because transmitting events doesnot allow a technician to scroll backward or forward. Thus, theprocessor 162 provides markers or pointers into the full disclosure ECGdata for the technician to review.

The processor 162 has a technician port 166 accessible by a techniciandevice 168 under the control of a technician. The technician uses thedevice 168 to view the results of the software analysis and for viewingand evaluating the full disclosure ECG data stored in the data centerstorage memory 148. In particular, the technician uses the device 168 toconsider any anomalies identified during the processing of the fulldisclosure ECG data by the data center processor 146 so that thetechnician via the technician device 168 can provide reports relating tothe technician's evaluation and/or relating to the identified anomalies.A physician port 170 accessible by a physician via a physician device172 views the provided technician reports and may view the fulldisclosure ECG data stored in the data center storage memory 148. As aresult, the system of FIG. 1 has the ability to telemeter fulldisclosure ECG data from patients at locations remote from the datacenter device 142, remote from the technician device 168 and remote fromthe physician device 172.

In one embodiment, the data center 142 includes the following softwarecomponents: a communications subsystem responsible for managing two waydata communications with the handheld devices 122; monitoringapplications as a primary interface used by technicians for reviewingfull disclosure ECG data and samples of arrhythmias contained in thefull disclosure ECG data, preparing reports and managing patient andbilling records; monitoring applications used by physician offices toreview reports and patient records; physician facing applications as aprimary web based interface used by physician offices for reviewingreports and patient clinical and billing information; an arrhythmiaanalysis subsystem which performs the automated arrhythmia analysisalgorithms on full disclosure ECG signals received from thecommunications subsystem and outputs annotations to storage andarrhythmia sample markers (or pointers) to the monitoring center webapplications; a reporting subsystem which generates, stores andtransmits clinical and billing reports; and device managementapplications providing visibility to device status as well asprovisioning and configuration.

The system 100 may be configured for two way communication between thepatient P and the physician device 172 and/or between the patient P andthe technician device 168. In one embodiment, this two way communicationmay be accomplished by two way communication between the handheld device122 and the data center 142 and between the data center 142 and themonitoring center 162. In this configuration, the system 100 has theability to transmit to the display 134 and/or the sound transducer 136of the handheld device 122 a custom text message and/or a voiceinstruction to the patient P from the technician device 168 via themonitoring center 162 and/or from the physician device 172 via themonitoring center 162 to meet a particular clinical need. Also, thepatient P may transmit a message from the handheld device 122 to thetechnician device 168 via the monitoring center 162 and/or from thephysician device 172 via the monitoring center 162.

In another embodiment, this two way communication may be accomplished bytwo way communication between the sensor device 102 and the handhelddevice 122, between the handheld device 122 and the data center 142 andbetween the data center 142 and the monitoring center 162. In thisconfiguration, the system 100 has the ability to transmit to the display116 of the sensor device 102 a custom text message and/or a voiceinstruction to the speaker 120 or a vibration alert to the vibrator 118from the technician device 168 via the monitoring center 162 and/or fromthe physician device 172 via the monitoring center 162 to alert thepatient P of a particular clinical need. Optionally, the body wornsensor 102 may have a keypad or microphone so that the patient P cantransmit a message from the sensor device 102 to the technician device168 via the monitoring center 162 and/or from the physician device 172via the monitoring center 162.

In one embodiment, near real-time streaming of the full disclosure ECGdata is available for viewing by the physician or technician via thedevices 168, 172. The sensor transmitter 110 streams in near real-timeto the handheld transmitter 128 an ECG signal down-sampled to 125 to 250Hz. In turn, the handheld transmitter 128 streams in near real-time tothe data center receiver 144 the packet signal. The data center 142streams ECG data included in the received packet signal 132 to thetechnician port 166 for near real-time viewing by the technician via thetechnician device 168. In addition, the data center 142 streams the ECGdata included in the received packet signal 132 to the physician port170 for near real-time viewing by the physician 172. In one embodiment,the handheld transmitter 130 transmits to the data center 142 packetsignals 132 with low latency to facilitate near real-time streaming.

In one embodiment, the sensor processor 106 includes an SADA (seriousarrhythmia detection algorithm) program which is executed by theprocessor (although it is contemplated that the handheld processor 126may have a SADA in addition to or instead of the sensor). The SADAprogram analyzes ECG down-sampled to 250 Hz in near real-time to detectcertain serious arrhythmias, as noted below. It is contemplated that theSADA program may be selectively executed only during periods when thehandheld and cellular network CN are not communicating and/or the sensormay execute the SADA when the sensor and handheld devices are notcommunicating. If the SADA is operating because the handheld device isnot communicating with the cell network but the sensor is communicatingwith the handheld device, and if conditions indicative of a seriousarrhythmia are detected, the sensor may alert the patient or may send asignal to the handheld so that the handheld alerts the patient or boththe sensor and handheld may alert the patient. Thus, the SADA programprovides an alert to the patient when one or more serious arrhythmiasare detected.

In one embodiment, the processor 126 of the handheld device 122 wouldselectively execute the SADA (Serious Arrhythmia Detection Algorithm) todetect serious arrhythmias. This detection would be enabled whenever thedevice is outside of communication range of the primary communicationslink, such as when the link is not present for more than three regularcommunication intervals. Also, the SADA may be capable of detectingventricular fibrillation and asystole. The handheld device 122 mayincorporate a lossless compression mechanism for compression of fulldisclosure ECG data. Alternatively or in addition, either the handhelddevice 122 and/or the sensor device 102 may support a lossy compressionalgorithm that will reduce the resolution of full disclosure ECG data inthe presence of noise. This algorithm should not reduce the resolutionof the data to less than 12 bits over a range of 10 mV. This renders thealgorithm lossless with respect to the requirements of AAMI EC38 fortype 1 devices. Also, if conditions indicative of a serious arrhythmiaare detected during a period when the device is outside of communicationrange of the primary communications link, the alert may include anindication to the patient to more to an area within the communicationrange of the primary communications link or the POTS modem.

The SADA may be implemented as illustrated in FIG. 5, executed by eitherthe sensor processor 106 or the handheld processor 126 or both. SuchSADA algorithms detect conditions indicative of serious arrhythmias suchas high heart rate (e.g., ventricular tachycardia and/or ventricularfibrillation, and/or asystole). In this embodiment, the SADA algorithmestimates the ratio of slow movements of the full disclosure ECG data(ventricular repolarization and baseline) vs. fast movements of the fulldisclosure ECG data (R-wave). This ratio is low for a normal rhythmbecause most of the time the full disclosure ECG data is trending arounda baseline. When the heart rate becomes higher, this ratio alsoincreases because fast movements of the full disclosure ECG data occurmore frequently as compared to slow baseline movements. The ratio isalso high for ventricular fibrillation rhythms because fast movements ofthe full disclosure ECG data occur frequently due to fibrillatingventricles. The SADA algorithm indicates when the analyzed heart rate isclose to or above 200 beats per minute (this number is an estimatebecause exact heart rate is not calculated). In this embodiment, theSADA algorithm includes band-pass filtering, low-pass filtering for thesignal, channel combination logic and a decision maker.

In addition, the decision maker holds an alarm for 30 seconds after theabove condition is changed to false. This prevents frequent retriggeringof the same condition.

In one form, the alert provided by the SADA program may be any one ormore of the following: providing an audible signal via the speaker 120of the body sensor device 102, providing a visual signal via a lighttransducer of the body sensor device 102 such as flashing the LED 116 ofthe body sensor device 102, providing a message on a display (not shown)of the body sensor device 102, flashing an LED (not shown) of thehandheld device 122, providing an audible signal via the soundtransducer 136 of the handheld device 122, providing a visual signal viaa light transducer (not shown) of the handheld device 122, and providinga message on the display 134 of the handheld device 122.

In one embodiment, as shown in FIG. 2, a modem may be used as analternative to connect the handheld device 122 to the data center 142,preferably as a back-up to the cellular network CN connection. Inparticular, the handheld transmitter 130 transmits a second signalincluding the full disclosure ECG data when the cellular network CN andhandheld device are not communicating. A modem, such as a POTS modem,located at the patient's site has a receiver for receiving the secondsignal including the full disclosure ECG data and a transmitter fortransmitting the full disclosure ECG data to the data center via a phoneline, a communications network, the Internet or some other internetprovider (IP) network. In one embodiment, a class 1 Bluetooth radio maybe used between the handheld device and a POTS (plain old telephonesystem) modem for more range.

As shown in the FIG. 2 embodiment, it is contemplated that the handheldin control of the POTS modem may communicate with the data center inseveral ways:

-   -   1) via a circuit switched data (CSD) connection which is a        direct connection between modems over the telephone line without        going over the internet or using an internet protocol (IP) on an        internal network. This would be a packet data protocol (not        necessarily IP) over CSD; or    -   2) via an Internet Protocol Network (e.g., technically over a        CSD connection) between the handheld using the modem and        terminating at an external (to the data center) ISP, after which        the signals are routed over a secure sockets protocol layer over        IP to the data center. This would be packet data (using Internet        Protocol) from the handheld to ISP to data center; or    -   3) via Internet Protocol to modems housed at the data center        directly (effectively the ISP is located in the data center).

Thus, in the embodiment of FIG. 2, the ISP could be located external tothe data center and use an IP to communicate with the servers in thedata center via the Internet or via a dedicated circuit. Alternatively,the ISP could be located in the data center and use an IP over aninternal network to transfer the data from the equipment housing theterminating modems to the DCS servers.

As shown in FIG. 2, the handheld device 122 may optionally access a WANand includes at least one of:

-   -   Graduated back off and PDP [Packet Data Protocol] context        re-connect algorithms;    -   Use of adaptive ECG resolution to reduce data payload;    -   Use of lossless compression to reduce data payload; and    -   Ability to connect to a home based POTS modem with a class 1 BT        Radio incorporated in the handheld.

Referring to FIG. 2, this embodiment illustrates a low power RFcommunication, such as class 3 Bluetooth, between the body worn sensorand the handheld device as compared to a higher power RF communication,such as class 1 Bluetooth, between the handheld device and the BT POTSmodem linking the handheld to the data center via a telephone line. Thepacket communication between the handheld device and the data center isestablished via cellular or other wireless network via a carrier link tothe data center via a VPN/leased line.

As illustrated, the data center would include a device communicationservice (DCS) for receiving and storing the packets of ECG data in adatabase, an EAPS (ECG Analysis and Processing Subsystem; see FIG. 3)for processing the ECG data, report and fax servers for providingreports and faxes to the physician, technician and/or patient. In otherwords, the DCS is the subsystem responsible for communications with thedevices in the field. EAPS performs the algorithm processing and ECGmanagement web application servers provides the database and userinterface. Additional servers can optionally be added to scale theapplication to support more users.

The results of the ECG data processed by the data center are availablein several different ways. The data center may be linked to themonitoring center by an IP network so that a certified cardiactechnician (CCT) may access the raw or processed data and reports. Inaddition, the data center may be linked to a physician device (computer)by a secure web connection so that the physician may access the raw orprocessed data and reports. In addition, the report and fax servers maybe linked by the Internet to a fax service for providing faxes over thepublic switched telephone network (PSTN).

FIG. 3 is a block diagram of one embodiment of the EAPS (ECG Analysisand Processing Subsystem) architecture of the data center of FIG. 2. Inone embodiment, an algorithm subsystem for analyzing each data stream ofeach patient will be run on the EAPS servers within the data center.Algorithm instances will be run simultaneously, one for each datastream, by the EAPS. The EAPS, which will start each algorithm instance,provides all data for processing, and collects results of dataprocessing. For example, the system would include a plurality of sensordevices 102 and a corresponding plurality of handheld devices 122. Eachhandheld device 122 would transmit a full disclosure ECG data packetsignal 132 to the data center 142. The data center includes a pluralityof algorithm instances for identifying anomalies in the ECG data and oneinstance is executed and applied to each full disclosure ECG data signalreceived by the data center.

When an algorithm instance processes full disclosure ECG data, it alsochanges its own internal state. This state is not carried over for thenext full disclosure ECG packet, but rather stored and sent back to theEAPS. When new full disclosure ECG data arrives, the EAPS sends thisstate information back to the algorithm instance along with the fulldisclosure ECG data. The algorithm instance itself does not hold a stateassociated with the full disclosure ECG data.

Upon startup, each algorithm instance will receive a unique TCP/IPaddress and port number for communication with the EAPS. Then, this portnumber will be used for communication with this particular instance.

FIG. 4 is a block diagram of one embodiment of the algorithm instance ofthe EAPS of the data center. Referring to FIGS. 3 and 4, each algorithminstance accepts full disclosure ECG data from a particular patient andreturns annotations indicating areas of interest (portions or samples ofthe full disclosure data) to a technician. In one embodiment, theinstance manager is a NT server and provides an interface for algorithminstances startup and registration with the EAPS manager, and algorithminstances shutdown. The instance manager keeps internal references forevery algorithm instance. These references are used for instance startupand shutdown. The mechanism of interaction between instance manager andalgorithm instances is native to the run-time environment (e.g., such asa Labview environment).

In one embodiment, each algorithm instance performs major tasks ofprocessing the full disclosure ECG data including at least one offiltering (e.g., preprocessing, artifact rejection), QRS detection,morphology detection and analysis, ventricular fibrillation (VFIB)detection, asystole detection, heart-rate calculations, and/or rhythmdetection (tachycardia, bradycardia, supraventricular tachycardia (SVT),atrial flutter (AF/AFL), ventricular tachycardia (V-tach) andidioventricular rhythm (IVR)). See FIG. 8, below.

As shown in FIG. 5, a ventricular fibrillation (VF) and/or SADAalgorithm which may be executed by the sensor device, the handhelddevice, or the data center (independent of any QRS detector). Thealgorithm receives full disclosure ECG samples at 250 Hz and, afterbandpass filtering, splits the data into two or more channels, eachchannel providing a high resolution full disclosure ECG acquisitionsignal (e.g., up to 1.25 microvolts per bit, 1000 Hz 16 bit samples persecond, dynamic range of +/−40 mV, 0.05 to 150 Hz bandpass). Eachchannel is processed symmetrically with additional filtering eitherbefore or after the processing. The channels are combined and decisionmaker logic is applied to identify samples of arrhythmia. The logic ofthe ventricular fibrillation detection algorithm may be the same as thelogic for the serious arrhythmia detection algorithm. However, theparameters of the VF detection algorithm are tuned to detect ventricularfibrillation only while the serious arrhythmia detection algorithmdecision maker may also be configured to identify samples of high heartrate ECG e.g., ventricular tachycardia.

Regarding the sample marker system of FIG. 4, once the QRS detectorprocesses the incoming full disclosure ECG data, the sample markersystem looks for samples of arrhythmia contained in this full disclosureECG packet using defined hard limits. Types of samples that areidentified include those in the following table:

Sample type Limit (Default) Limit Range Pause/Asystole >3 seconds 2-5seconds Bradycardia <40 bpm 20-50 bpm Tachycardia >180 bpm 120-220 bpmSVT >30 sec 5-60 sec VT Rate: >110 bpm Rate: 80-150 bpm (3 or morebeats) Beats: 3-10 Idioventricular >30 beats 5-50 beats Rhythm VF AlwaysAF First onset for patient 1-10 Onsets Then Vrate >150 or <40 Vrate:20-220 bpm BPM Patient Initiated Always sent

Values of hard limits could be changed from defaults for any patient atany time. The algorithm is receiving hard limit values from the EAPS andgenerating sample markers according to received hard limits. A graphicalrepresentation of hard limit based sample identification is shown inFIG. 6. It is important to differentiate between “hard limit” and “softlimit” algorithms. SADA and what was formerly called the “representativeevent” algorithm are examples of soft limit algorithms. Soft limitalgorithms include pre-defined thresholds which are not discrete whereashard limit only include pre-defined thresholds.

A soft limit sample marker algorithm may be employed by the data centerprocessor 146 for post-processing of patient's data. A soft limitalgorithm can be used to identify samples when the hard limit detectordoes not detect any. These ECG samples are chosen in a way that wouldreflect the most serious of any particular samples that do not meet thehard limit criteria (e.g., lowest and highest heart rates for the day ornight or longest pause). Soft limit samples types may be one or more ofthe following: tachycardia, bradycardia, and/or a pause.

Soft limit samples are generated for previously processed data:annotations are assumed to be available for the time interval ofinterest (usually, the last 24 hours). One form of an algorithm to softlimit samples is the following:

-   -   time interval of 10 minutes before the existing sample of the        same type and 10 minutes after the existing sample is excluded        from processing.    -   remaining data are analyzed for maximum severity and absence of        artifacts, and based on this information, the best samples are        marked from full disclosure ECG data and the corresponding soft        limits samples are marked.

The severity of samples of arrhythmias is calculated accordingly to thesample type:

-   -   highest heart rate for a tachycardia sample type,    -   lowest heart rate for a bradycardia sample type, and    -   longest pause for a pause sample type.        It is important to note that soft limits samples do not have a        predefined limit as a criterion for sample marking.

In operation, the system would be used as follows according to oneexample of one embodiment. The system would include a plurality ofsensors 102 and a corresponding plurality of handheld devices 122, allsimultaneously transmitting full disclosure ECG data packet signals viathe cell network CN to the data center 142. The leads 112 would beattached to the patient who would be wearing the sensor device 102. Ifthe leads fall off the patient or otherwise are not detecting ECG data,the sensor device 102 would alert the patient and send an alert to atechnician via the data center. The patient would carry the handhelddevice 122 and install a modem at the patient's location for back-upconnectivity. In the event that the sensor 102 is out of range of thehandheld device 122, such as if the patient forgets to carry thehandheld device 122, no data is lost because the sensor stores all data.The sensor may alert the patient that the sensor is out of range of thehandheld device. In the event that the handheld device is notcommunicating with the data center via the cell network, the handhelddevice would attempt to communicate via the modem. If communication withthe data center is not available, no data is lost because the sensorstores all data.

In one embodiment, the system may be configured for use by a patienthaving access to a cellular network for monitoring patient parametersother than ECG data. For example, the system would comprise the bodysensor device adapted to be worn by the patient and having a sensorcircuit detecting a full disclosure analog signal of a parameterindicative of a body function of the patient. The sensor processorstores full disclosure data corresponding to the detected analog signalin the sensor storage memory, and the sensor transmitter transmits afull disclosure signal including the full disclosure data stored in thesensor storage memory. Similarly, the handheld receiver receives thefull disclosure signal, the handheld processor stores the fulldisclosure data included in the received full disclosure signal in thehandheld storage memory, and the handheld transmitter transmits a packetsignal including the full disclosure data stored in the handheld storagememory via the cellular network. The data center receiver receives thepacket signal, the data center processor stores the full disclosure dataincluded in the received packet signal in the data center storagememory, and the data center processor analyzes the full disclosure datastored in the data center storage memory to identify any parameteranomalies in the full disclosure data stored in the data center storagememory. The monitoring center permits the technician/physician device toevaluate the full disclosure data stored in the data center storagememory, for considering any identified parameter anomalies and forproviding reports. As a result, the system has the ability to telemeterfull disclosure parameter data from remote locations. As a specificexample, modalities of the system may include monitoring parameterswhich indicate one or more of the following:

a sensor circuit detecting a full disclosure analog ECG signalindicative of the heart of the patient;

a sensor circuit detecting a full disclosure analog blood pressuresignal indicative of the blood pressure of the patient;

a sensor circuit detecting a full disclosure analog body temperaturesignal indicative of the body temperature of the patient;

a sensor circuit detecting a full disclosure analog uterine contractionsignal indicative of the contractions of the uterine of the patient;

a sensor circuit detecting a full disclosure analog signal indicative ofthe level (e.g., pulse oxygen) of the patient.

In one embodiment, several parameters, such as ECG and blood pressuredata, may be simultaneously sensed, transmitted and analyzed by thesystem.

In one embodiment, it is contemplated that the sensor device 102 couldbe used as a stand-alone device as a holter recorder. In thisembodiment, the sensor device 102 would include a USB or similar port orBT functionality to connect to a personal computer for downloading theholter data.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing from thescope of the invention defined in the appended claims.

For purposes of illustration, programs and other executable programcomponents, such as the operating system, are illustrated herein asdiscrete blocks. It is recognized, however, that such programs andcomponents reside at various times in different storage components ofthe computer, and are executed by the data processor(s) of the computer.

Although described in connection with an exemplary computing systemenvironment, embodiments of the invention are operational with numerousother general purpose or special purpose computing system environmentsor configurations. The computing system environment is not intended tosuggest any limitation as to the scope of use or functionality of anyaspect of the invention. Moreover, the computing system environmentshould not be interpreted as having any dependency or requirementrelating to any one or combination of components illustrated in theexemplary operating environment. Examples of well known computingsystems, environments, and/or configurations that may be suitable foruse with aspects of the invention include, but are not limited to,personal computers, server computers, hand-held or laptop devices,multiprocessor systems, microprocessor-based systems, set top boxes,programmable consumer electronics, mobile telephones, network PCs,minicomputers, mainframe computers, distributed computing environmentsthat include any of the above systems or devices, and the like.

Embodiments of the invention may be described in the general context ofcomputer-executable instructions, such as program modules, executed byone or more computers or other devices. Generally, program modulesinclude, but are not limited to, routines, programs, objects,components, and data structures that perform particular tasks orimplement particular abstract data types. Aspects of the invention mayalso be practiced in distributed computing environments where tasks areperformed by remote processing devices that are linked through acommunications network. In a distributed computing environment, programmodules may be located in both local and remote computer storage mediaincluding memory storage devices.

In operation, computers and/or servers may execute thecomputer-executable instructions such as those illustrated herein toimplement aspects of the invention.

The order of execution or performance of the operations in embodimentsof the invention illustrated and described herein is not essential,unless otherwise specified. That is, the operations may be performed inany order, unless otherwise specified, and embodiments of the inventionmay include additional or fewer operations than those disclosed herein.For example, it is contemplated that executing or performing aparticular operation before, contemporaneously with, or after anotheroperation is within the scope of aspects of the invention.

Embodiments of the invention may be implemented with computer-executableinstructions. The computer-executable instructions may be organized intoone or more computer-executable components or modules on a tangiblecomputer readable storage medium. Aspects of the invention may beimplemented with any number and organization of such components ormodules. For example, aspects of the invention are not limited to thespecific computer-executable instructions or the specific components ormodules illustrated in the figures and described herein. Otherembodiments of the invention may include different computer-executableinstructions or components having more or less functionality thanillustrated and described herein.

When introducing elements of aspects of the invention or the embodimentsthereof, the articles “a,” “an,” “the,” and “said” are intended to meanthat there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements.

In view of the above, it will be seen that several advantages of theinvention are achieved and other advantageous results attained.

Having described aspects of the invention in detail, it will be apparentthat modifications and variations are possible without departing fromthe scope of aspects of the invention as defined in the appended claims.As various changes could be made in the above constructions, products,and methods without departing from the scope of aspects of theinvention, it is intended that all matter contained in the abovedescription and shown in the accompanying drawings shall be interpretedas illustrative and not in a limiting sense.

1. A system for use by a patient having access to a cellular networkcomprising: a body sensor device adapted to be worn by the patient andhaving a sensor circuit, a sensor processor, a sensor storage memory anda sensor transmitter, wherein the sensor circuit detects an analog fulldisclosure ECG signal of the patient, wherein the sensor processorstores full disclosure ECG data corresponding to the detected analogsignal in the sensor storage memory, and wherein the sensor transmittertransmits a full disclosure ECG signal including the full disclosure ECGdata stored in the sensor storage memory; a handheld device adapted tobe carried by the patient and having a handheld storage memory, ahandheld processor, a handheld receiver and a handheld transmitter,wherein the handheld receiver receives the full disclosure ECG signal,wherein the handheld processor stores the full disclosure ECG dataincluded in the received full disclosure ECG signal in the handheldstorage memory, and wherein the handheld transmitter transmits a packetsignal including the full disclosure ECG data stored in the handheldstorage memory via the cellular network; a data center remote from thepatient and having a data center receiver, a data center processor and adata center storage memory, wherein the data center receiver receivesthe packet signal, wherein the data center processor stores the fulldisclosure ECG data included in the received packet signal in the datacenter storage memory, and wherein the data center processor analyzesthe full disclosure ECG data stored in the data center storage memory toidentify any anomalies in the full disclosure ECG data stored in thedata center storage memory; a monitoring center linked to the datacenter and having a technician port accessible by a technician devicefor evaluating the full disclosure ECG data stored in the data centerstorage memory, for considering any identified anomalies and forproviding reports, and a physician port accessible by a physician forviewing provided technician reports and for viewing the full disclosureECG data stored in the data center storage memory, whereby the systemhas the ability to telemeter full disclosure ECG data from remotelocations.
 2. The system of claim 1 wherein the sensor transmitterstreams the full disclosure ECG signal including the full disclosure ECGdata in near real-time almost immediately after the detected fulldisclosure ECG data is stored in the sensor storage memory, wherein thehandheld transmitter streams the packet signal including the fulldisclosure ECG data almost immediately after the full disclosure ECGdata is stored in the handheld storage memory and wherein the datacenter streams the full disclosure ECG data included in the receivedpacket signal to the technician port for near real-time viewing by thetechnician and/or wherein the data center streams the full disclosureECG data included in the received packet signal to the physician portfor near real-time viewing by the physician.
 3. The system of claim 1wherein the data center presents the technician or physician with anoption to view full disclosure ECG data which is previous to and/orsubsequent to the full disclosure data being viewed.
 4. The system ofclaim 1 wherein the data center processes the full disclosure ECG datafrom multiple patients simultaneously.
 5. The system of claim 1 furthercomprising two way communication between the handheld device and thedata center and between the data center and the monitoring center suchthat the system has the ability to transmit to a transducer of thehandheld device a voice instruction to the patient from the technicianvia the monitoring center and/or from the physician via the monitoringcenter to meet a particular clinical need.
 6. The system of claim 1wherein the full disclosure ECG signal acquired by the body sensordevice comprises at least 2 channels of data from the sensor, eachchannel providing a high resolution full disclosure ECG acquisitionsignal.
 7. The system of claim 1 wherein the full disclosure ECG signalacquired by the body sensor device comprises at least 2 channels, eachproviding a dynamic range of +/−40 mV.
 8. The system of claim 1 whereinthe data center incorporates a muscle artifact rejection algorithm fornoise rejection.
 9. The system of claim 1 wherein the handheld devicecomprises an integrated application and baseband processor in apre-certified module.
 10. The system of claim 1 wherein the handhelddevice accesses a WAN and includes at least one of: Graduated back offand PDP context re-connect algorithms; Use of adaptive full disclosureECG resolution to reduce data payload; Use of lossless compression toreduce data payload; and Ability to connect to a home based POTS modemwith a class 1 BT Radio incorporated in the handheld device.
 11. Thesystem of claim 1 further comprising a modem connected to the datacenter via the Internet or a phone line, wherein the handheldtransmitter transmits a second signal including the full disclosure ECGdata to the modem when the handheld is not communicating with thecellular network and wherein said modem has a receiver for receiving thesecond signal including the full disclosure ECG data and a transmitterfor transmitting the full disclosure ECG data to the data center via theInternet or the phone line.
 12. The system of claim 1 wherein thehandheld transmitter transmits the packet signal with low latency. 13.The system of claim 1 wherein the body sensor device is battery powered,wherein the handheld device is battery powered, wherein the body sensordevice transmits to the handheld device information indicative of itsbattery level, and wherein the handheld device includes a display fordisplaying the battery levels of both the body sensor device and thehandheld device.
 14. The system of claim 1 wherein the body sensordevice and/or the handheld storage memory comprises at least 30 days offull disclosure full disclosure ECG data storage.
 15. The system ofclaim 1 wherein the body sensor device and the handheld devicecommunicate via a low power local RF link protocol for power saving. 16.The system of claim 1 wherein the sensor processor includes a seriousarrhythmia detection algorithm (SADA) which is executed by theprocessor, said SADA program analyzing at a low resolution in nearreal-time the full disclosure ECG data stored in its memory to detectany predefined arrhythmia events when the sensor device and the handhelddevice are not communicating or when the handheld device is notcommunicating with the cellular network, and wherein the SADA programprovides an alert to the patient when one or more events is detected.17. The system of claim 1 wherein the data center processor provides afull disclosure navigable waveform that provides drill down access toportions of a particular day's full disclosure ECG data by presenting asecondary measure such as HR or noise level of the full disclosure ECGdata.
 18. The system of claim 1 wherein the data center permits thetechnician and/or the physician to view the stored full disclosure ECGdata in low resolution and to drill down selected full disclosure ECGdata at a higher resolution.
 19. The system of claim 1 wherein the datacenter permits the technician and/or the physician to view the storedfull disclosure ECG data of a particular period of time and to viewrelated ECG data before or after the particular period of time.
 20. Thesystem of claim 1 further comprising a plurality of sensor devices and acorresponding plurality of handheld devices, each handheld devicetransmitting a full disclosure ECG data signal to the data center,wherein the data center includes a plurality of algorithm instances foridentifying anomalies in the ECG data and wherein one instance isexecuted and applied to each full disclosure ECG data signal received bythe data center.
 21. A system for use by a patient having access to acellular network, said system comprising: a body sensor device adaptedto be worn by the patient and having a sensor circuit, a sensorprocessor, a sensor storage memory and a sensor transmitter, wherein thesensor circuit detects a full disclosure analog signal of a parameterindicative of a body function of the patient, wherein the sensorprocessor stores full disclosure data corresponding to the detectedanalog signal in the sensor storage memory, and wherein the sensortransmitter transmits a full disclosure signal including the fulldisclosure data stored in the sensor storage memory; a handheld deviceadapted to be carried by the patient and having a handheld storagememory, a handheld processor, a handheld receiver and a handheldtransmitter, wherein the handheld receiver receives the full disclosuresignal, wherein the handheld processor stores the full disclosure dataincluded in the received full disclosure signal in the handheld storagememory, and wherein the handheld transmitter transmits a packet signalincluding the full disclosure data stored in the handheld storage memoryvia the cellular network; a data center remote from the patient andhaving a data center receiver, a data center processor and a data centerstorage memory, wherein the data center receiver receives the packetsignal, wherein the data center processor stores the full disclosuredata included in the received packet signal in the data center storagememory, and wherein the data center processor analyzes the fulldisclosure data stored in the data center storage memory to identify anyparameter anomalies in the full disclosure data stored in the datacenter storage memory; a monitoring center linked to the data center andhaving a technician port accessible by a technician device forevaluating the full disclosure data stored in the data center storagememory, for considering any identified anomalies and for providingreports, and a physician port accessible by a physician for viewingprovided technician reports and for viewing the full disclosure datastored in the data center storage memory, whereby the system has theability to telemeter full disclosure parameter data from remotelocations.
 22. The system of claim 21 wherein the sensor comprises atleast one of: a sensor circuit detecting a full disclosure analog ECGsignal indicative of the heart of the patient; a sensor circuitdetecting a full disclosure analog blood pressure signal indicative ofthe blood pressure of the patient; a sensor circuit detecting a fulldisclosure analog body temperature signal indicative of the bodytemperature of the patient; a sensor circuit detecting a full disclosureanalog uterine contraction signal indicative of the contractions of theuterine of the patient; a sensor circuit detecting a full disclosureanalog signal indicative of the level of the patient.